American Association for Cancer Research
10780432ccr152614-sup-157253_2_supp_3403000_k41t5r.png (4.76 MB)

Supplementary figure 1 from OX40+ Regulatory T Cells in Cutaneous Squamous Cell Carcinoma Suppress Effector T-Cell Responses and Associate with Metastatic Potential

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posted on 2023-03-31, 18:18 authored by Chester Lai, Suzannah August, Amel Albibas, Ramnik Behar, Shin-Young Cho, Marta E. Polak, Jeffrey Theaker, Amanda S. MacLeod, Ruth R. French, Martin J. Glennie, Aymen Al-Shamkhani, Eugene Healy

Supplementary figure 1: Characterization of the cSCC immune infiltrate demonstrates the presence of tumoral Tregs.


Wellcome Trust

National Institute for Health Research

Ministry of Higher Education and Scientific Research

Cancer Research UK


Duke University



Purpose: Cutaneous squamous cell carcinoma (cSCC) is the most common human cancer with metastatic potential. Despite T cells accumulating around cSCCs, these tumors continue to grow and persist. To investigate reasons for failure of T cells to mount a protective response in cSCC, we focused on regulatory T cells (Tregs) as this suppressive population is well represented among the infiltrating lymphocytes.Experimental Design: Flow cytometry was conducted on cSCC lymphocytes and in vitro functional assays were performed using sorted tumoral T cells. Lymphocyte subsets in primary cSCCs were quantified immunohistochemically.Results: FOXP3+ Tregs were more frequent in cSCCs than in peripheral blood (P < 0.0001, n = 86 tumors). Tumoral Tregs suppressed proliferation of tumoral effector CD4+ (P = 0.005, n = 10 tumors) and CD8+ T cells (P = 0.043, n = 9 tumors) and inhibited IFNγ secretion by tumoral effector T cells (P = 0.0186, n = 11 tumors). The costimulatory molecule OX40 was expressed predominantly on tumoral Tregs (P < 0.0001, n = 15 tumors) and triggering OX40 with an agonist anti-OX40 antibody overcame the suppression exerted by Tregs, leading to increased tumoral effector CD4+ lymphocyte proliferation (P = 0.0098, n = 10 tumors). Tregs and OX40+ lymphocytes were more abundant in primary cSCCs that metastasized than in primary cSCCs that had not metastasized (n = 48 and n = 49 tumors, respectively).Conclusions: Tregs in cSCCs suppress effector T-cell responses and are associated with subsequent metastasis, suggesting a key role for Tregs in cSCC development and progression. OX40 agonism reversed the suppressive effects of Tregs in vitro, suggesting that targeting OX40 could benefit the subset of cSCC patients at high risk of metastasis. Clin Cancer Res; 22(16); 4236–48. ©2016 AACR.